Abstract: A method for determining an optimum or maximum-permissible speed of a rail vehicle, dependent on a thermal state of at least one friction element of at least one friction brake of includes detecting at least one parameter which characterizes a current operating situation of the rail vehicle, determining or estimating a first influence on the thermal state of the at least one friction element based on the current operating situation of the rail vehicle, determining or estimating a second influence on the thermal state of the at least one friction element, determining the optimum or maximum-permissible speed of the rail vehicle in such a way that an allowed friction-element maximum temperature of the at least one friction element is not exceeded, or the allowed friction-element maximum temperature of the at least one friction element is substantially obtained, at the at least one friction element under the first or second influence.

Abstract: The contact spring arrangement has an elongated contact spring having a rigid connecting leg which extends approximately parallel to the contact spring and conducts the switching current in a direction opposite to the contact spring. On the side opposite the connecting leg the contact spring has a contact piece which co-operates with an opposite counter-contact element having a contact piece. The repulsive forces between the connecting leg and the contact spring become so long that even in the case of the highest short circuit currents no welding of the contacts results when in the case of contact pieces made from silver or a silver alloy the length of the gap formed between the contact spring and connecting leg is at least 20 times larger than the average spring spacing in the gap.